From patchwork Mon Jan 30 11:30:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 13120940 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C2FEC54EAA for ; Mon, 30 Jan 2023 11:30:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236633AbjA3Laz (ORCPT ); Mon, 30 Jan 2023 06:30:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236287AbjA3Lax (ORCPT ); Mon, 30 Jan 2023 06:30:53 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D4713A5F8; Mon, 30 Jan 2023 03:30:52 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 92B7C1FDCA; Mon, 30 Jan 2023 11:30:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1675078251; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7yVMurcsGHiv7+xYW4/H+27IaQd8JYSho/wI2BZnRUo=; b=aijfbGWyINlAMInGEsZDxevlTHYbORDnN3QQ1jpwwDmlpS36DxGTeiXH1lzJ9NItp7Pbv6 TPATiiNGtSYQgYhqv2TlPHK5iViEifKoKRva0J5rrzRmKoLmfEbjpc08KqSDnKvFUCzCTS GtVXKwps13Vht1WSzXCF3ILjfYWwvLA= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 41C6613A06; Mon, 30 Jan 2023 11:30:51 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id XTO2Dmuq12PWJQAAMHmgww (envelope-from ); Mon, 30 Jan 2023 11:30:51 +0000 From: Juergen Gross To: linux-kernel@vger.kernel.org, v9fs-developer@lists.sourceforge.net, netdev@vger.kernel.org Cc: Juergen Gross , Eric Van Hensbergen , Latchesar Ionkov , Dominique Martinet , Christian Schoenebeck , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Subject: [PATCH 2/2] 9p/xen: fix connection sequence Date: Mon, 30 Jan 2023 12:30:36 +0100 Message-Id: <20230130113036.7087-3-jgross@suse.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20230130113036.7087-1-jgross@suse.com> References: <20230130113036.7087-1-jgross@suse.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Today the connection sequence of the Xen 9pfs frontend doesn't match the documented sequence. It can work reliably only for a PV 9pfs device having been added at boot time already, as the frontend is not waiting for the backend to have set its state to "XenbusStateInitWait" before reading the backend properties from Xenstore. Fix that by following the documented sequence [1] (the documentation has a bug, so the reference is for the patch fixing that). [1]: https://lore.kernel.org/xen-devel/20230130090937.31623-1-jgross@suse.com/T/#u Fixes: 868eb122739a ("xen/9pfs: introduce Xen 9pfs transport driver") Signed-off-by: Juergen Gross Reviewed-by: Simon Horman --- net/9p/trans_xen.c | 38 +++++++++++++++++++++++--------------- 1 file changed, 23 insertions(+), 15 deletions(-) diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c index ad2947a3b376..c64050e839ac 100644 --- a/net/9p/trans_xen.c +++ b/net/9p/trans_xen.c @@ -372,12 +372,11 @@ static int xen_9pfs_front_alloc_dataring(struct xenbus_device *dev, return ret; } -static int xen_9pfs_front_probe(struct xenbus_device *dev, - const struct xenbus_device_id *id) +static int xen_9pfs_front_init(struct xenbus_device *dev) { int ret, i; struct xenbus_transaction xbt; - struct xen_9pfs_front_priv *priv = NULL; + struct xen_9pfs_front_priv *priv = dev_get_drvdata(&dev->dev); char *versions, *v; unsigned int max_rings, max_ring_order, len = 0; @@ -405,11 +404,6 @@ static int xen_9pfs_front_probe(struct xenbus_device *dev, if (p9_xen_trans.maxsize > XEN_FLEX_RING_SIZE(max_ring_order)) p9_xen_trans.maxsize = XEN_FLEX_RING_SIZE(max_ring_order) / 2; - priv = kzalloc(sizeof(*priv), GFP_KERNEL); - if (!priv) - return -ENOMEM; - - priv->dev = dev; priv->num_rings = XEN_9PFS_NUM_RINGS; priv->rings = kcalloc(priv->num_rings, sizeof(*priv->rings), GFP_KERNEL); @@ -468,23 +462,35 @@ static int xen_9pfs_front_probe(struct xenbus_device *dev, goto error; } - write_lock(&xen_9pfs_lock); - list_add_tail(&priv->list, &xen_9pfs_devs); - write_unlock(&xen_9pfs_lock); - dev_set_drvdata(&dev->dev, priv); - xenbus_switch_state(dev, XenbusStateInitialised); - return 0; error_xenbus: xenbus_transaction_end(xbt, 1); xenbus_dev_fatal(dev, ret, "writing xenstore"); error: - dev_set_drvdata(&dev->dev, NULL); xen_9pfs_front_free(priv); return ret; } +static int xen_9pfs_front_probe(struct xenbus_device *dev, + const struct xenbus_device_id *id) +{ + struct xen_9pfs_front_priv *priv = NULL; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->dev = dev; + dev_set_drvdata(&dev->dev, priv); + + write_lock(&xen_9pfs_lock); + list_add_tail(&priv->list, &xen_9pfs_devs); + write_unlock(&xen_9pfs_lock); + + return 0; +} + static int xen_9pfs_front_resume(struct xenbus_device *dev) { dev_warn(&dev->dev, "suspend/resume unsupported\n"); @@ -503,6 +509,8 @@ static void xen_9pfs_front_changed(struct xenbus_device *dev, break; case XenbusStateInitWait: + if (!xen_9pfs_front_init(dev)) + xenbus_switch_state(dev, XenbusStateInitialised); break; case XenbusStateConnected: